1. Technical Field
The present disclosure relates generally to light emitting devices, and more particularly to a method of manufacturing a vertical light emitting diode (LED).
2. Description of Related Art
Generally, a nitride-based semiconductor LED is grown on a sapphire substrate, but the sapphire substrate is a rigid nonconductor and has poor thermal conductivity. Therefore, there is a limitation in reducing the manufacturing costs by reducing the size of a nitride-based semiconductor LED, or improving the optical power and chip characteristic. Particularly, because the application of a high current is essential for achieving high power LED, it is important to solve a heat dissipation problem of the LED. To solve this problem, there has been proposed a vertical LED in which a sapphire substrate is removed by using a laser lift off (LLO) technique or a lapping process.
However, the LLO technique may be inadequate and inefficient for manufacturing large size LED due to a high cost thereof. In addition, cracks may occur at the edge of a light emitting structure of the LED, which reduces the reliability of the LED. Although the lapping process has the advantage of low cost and high efficiency compared with the LLO technique, it is difficult to differentiate the interface between different layers of the LED, resulting in a high risk of damage of the light emitting structure of the LED.
What is needed therefore is a method of manufacturing a vertical light emitting diode which can overcome the above mentioned limitations.